mtd: spi-nor: Remove recently added spi_nor_wait_till_ready() call

Remove undocumented spi_nor_wait_till_ready() call. This was added in commit
5d40b3d384dc ("mtd: spi-nor: Add parallel and stacked memories support")
without any explanation in the commit message. Remove it.

Fixes: 5d40b3d384dc ("mtd: spi-nor: Add parallel and stacked memories support")
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index 8dfdcda..0b131ad 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -1631,10 +1631,6 @@
 		if (read_len == 0)
 			return -EIO;
 
-		ret = spi_nor_wait_till_ready(nor);
-		if (ret)
-			goto read_err;
-
 		ret = nor->read(nor, offset, read_len, buf);
 		if (ret == 0) {
 			/* We shouldn't see 0-length reads */
@@ -2018,10 +2014,6 @@
 		page_remain = min_t(size_t,
 				    nor->page_size - page_offset, len - i);
 
-		ret = spi_nor_wait_till_ready(nor);
-		if (ret)
-			goto write_err;
-
 		write_enable(nor);
 		/*
 		 * On DTR capable flashes like Micron Xcella the writes cannot